Disease relevance of Area Postrema

• Studies in rats and rabbits indicate that angiotensin II (Ang II)-dependent hypertension is abolished by lesioning of the area postrema [1].
• Electrical stimulation of the dog's area postrema (AP) induces a response that mimics the pressor response produced by intravertebral infusion of low-dose angiotensin II, which causes an increase in mean arterial pressure associated with transient tachycardia and increased peripheral resistance [2].
• Summarizing, we firstly describe a marked and highly confined expression of the extraneuronal monoamine transporter in the rat area postrema by in situ hybridisation which may play a role in physiological functions of this circumventricular organ such as emesis, food intake and the regulation of cardiovascular functions [3].
• Nitroprusside-induced isovolemic hypotension yielded a pattern of c-fos induction similar to that seen following hemorrhage, except in the area postrema and the A1 cell group, where the response was muted or lacking [4].
• Hyperthermia induced Hsp27 IR in neurons of the subfornical organ and the area postrema within 3 hours and reached a maximum by 24 hours with a return to control levels 4-6 days after hyperthermia [5].

Psychiatry related information on Area Postrema

• Conditioned taste aversions and changes in motor activity in lithium-treated rats. Mediating role of the area postrema [6].

High impact information on Area Postrema

• Response of mesencephalic and hypothalamic dopamine neurones to alpha-MSH: mediated by area postrema [7]?
• Another peptide, arginine vasopressin (AVP), has been shown to enhance the sympathoinhibitory influence of the arterial baroreflex via an action at the area postrema [1].
• In the adult mouse brain, Brn-3b is found only within cells in the deep layers of the superior colliculus, in the dorsal periaqueductal gray, and in a small cluster of cells in the brain stem near the area postrema [8].
• This action is apparently mediated via Ang II receptors in the area postrema, but it is not known if these are of the AT1 or AT2 subtype [9].
• Both OXM and the GLP-1R agonist exendin-4 (Ex-4) activated neuronal c-fos expression in the paraventricular nucleus of the hypothalamus, the area postrema, and the nucleus of the solitary tract following intraperitoneal (i.p.) injection [10].

Chemical compound and disease context of Area Postrema

• The area postrema in deoxycorticosterone-salt hypertension in rats [11].
• Noradrenaline-induced emesis. Alpha-2 adrenoceptor mediation in the area postrema [12].
• In confirmation of our previous study, hypertension produced by phenylephrine resulted in the neuronal expression of Fos (a marker of neuronal activation) in the nucleus of the solitary tract, area postrema, the intermediate and caudal parts of the ventrolateral medulla parabrachial complex, and in the central nucleus of the amygdala [13].
• 5. Cisplatin-induced emesis was not inhibited by discrete injection of ketanserin (30 micrograms) or methiothepin (30 micrograms) into the area postrema [14].
• These cats then vomited appropriately in response to the injection of deslanoside which induces emesis through an action on the area postrema [15].

Biological context of Area Postrema

• Specific high-density binding sites have been found in the brain, especially in the hypothalamus, subfornical organ, median eminence, area postrema, and nucleus tractus solitarius, all areas involved in the brain control of hypertension and in the regulation of salt and water [16].
• Analysis of the competition curves revealed that in the choroid plexus, pia-arachnoid, olfactory bulb, subfornical organ, area postrema, and habenular nucleus, ANF interacts with its binding sites with high affinity (IC50, 0.46-0.77 nM) [17].
• Role of area postrema in transgene hypertension [18].
• This study reports the effects of angiotensin II (ANG II), arginine vasopression (AVP), phenylephrine (PE), and sodium nitroprusside (SNP) on baroreflex control of heart rate in the presence and absence of the area postrema (AP) in conscious mice [19].
• In the cat area postrema, a range of cell sizes were immunostained with the GABA antibody [20].

Anatomical context of Area Postrema

• A central site of action of circulating vasopressin may be the area postrema, since it is the only circumventricular organ in the hindbrain [21].
• Topical suffusion of adenosine and ADP produced similar dose-related dilation of arterioles to area postrema and dorsal brain stem [22].
• The greatest numbers of catecholaminergic neurons in the ventrolateral reticular formation (A1/C1 group) were located in the far rostral medulla, whereas the largest populations of catecholaminergic cells in the dorsal vagal complex (A2/C2 group) were found at the level of the area postrema [23].
• For the posterior hindbrain, we identify retinoic acid as an important signal to induce NA differentiation in the medulla oblongata and area postrema, where it expands the tfap2a expression domain and thus acts upstream of tfap2a [24].
• GK mRNA was also found in the area postrema/nucleus tractus solitarius region by RT-PCR [25].

Associations of Area Postrema with chemical compounds

• Reflex effect of vasopressin after blockade of V1 receptors in the area postrema [26].
• Lesioning the region of the area postrema resulted in a normalization of the responses evoked with arginine-vasopressin and phenylephrine [21].
• This study investigated the effect of micropressure injection of the V1 arginine vasopressin (AVP) receptor antagonist into the area postrema on the ability of circulating AVP to augment baroreflex inhibition of renal sympathetic nerve activity (RSNA) in urethane-anesthetized rabbits [26].
• L-NMMA microinjected into the area postrema did not alter AP, HR, or RSNA [27].
• Extravasation of sodium fluorescein (MW, 386), but not 150 kDa (MW) fluorescein isothiocyanate-dextran, occurred in the area postrema under control conditions [22].

Gene context of Area Postrema

• In situ hybridization histochemistry failed to detect constitutive expression of the chemokine transcript in the cerebral tissue except for the area postrema (AP) that exhibited a low signal under basal conditions [28].
• The results presented here extend our previous finding of expression of the Celsr1 receptor in the embryo and show that expression continues into adult life when expression in the brain is localized principally in the ependymal cell layer, choroid plexus, and the area postrema [29].
• The results indicate that DOCA and DEX may increase the sensitivity of the brain to the behavioral and physiological actions of AngII by upregulating AT1 receptors in the SFO and area postrema [30].
• Systemic ADM gains access to the brain through the area postrema (AP), a brainstem circumventricular organ, and the PVN is a major target of these ADM-sensitive AP neurons [31].
• The most remarkable finding was the detection of a strong signal for Notch2 mRNA in two circumventricular organs: the subfornical organ and the area postrema [32].

Analytical, diagnostic and therapeutic context of Area Postrema

• Neither abdominal vagotomy nor area postrema lesions reliably altered Fos expression induced in the medulla or PVH in response to a moderately suprathreshold dose of IL-1beta [33].
• Stereotaxic microinjection (60 nL) of adenosine was made into the nucleus tractus solitarii and the area postrema and was confirmed histologically [34].
• In situ hybridization on the medaka brain shows that meNET mRNA is present only in a subset of tyrosine hydroxylase-positive neurons found in the noradrenergic areas of the hindbrain, such as the locus ceruleus and area postrema [35].
• Whole-cell recordings were made from dorsomedial nucleus tractus solitarii neurons in thin coronal medullary slices of the rat, at the level of the area postrema [36].
• Biochemical study of the NGF receptor showed a major band of molecular weight of approximately 90 KDa in the area postrema, choroid plexus, median eminence, and medial septum with the relative content consistent with that seen by immunohistochemistry [37].

References